After probing the moon, Chinese satellite Chang'e II left the lunar orbit and began to explore asteroid No. 4179 which is 7 million km away from Earth. The country also set out plans to send retrievable rovers to the moon by 2017.

Chang'e II's successful mission of exploring and orbiting the Moon marks one of China's space exploration milestones. The satellite flew to the 4.6km by 4.6km-asteroid No. 4179, which impact could equal that of 500 million Hiroshima atomic bombs should it hit Earth.

The country also plans to launch Chang'e III, which is equipped with cameras and basic analyzing instruments, to the lunar surface in 2013 and to send Chang'e VI--a retrievable, sample-collecting robot--by 2017.

"We are going to encounter a lot of problems during the course," Ouyang Ziyuan, the chief scientist of China's moon exploring project, told a Chinese technology newspaper. "First is [to focus on] the landing, and also to let the robot function properly in the hash lunar environment."

The temperature on the moon could reach 120℃ during the day, and plummet to -180℃ in the night. The charged dust on the moon could also be a challenge to the solar panels and optical instruments.

"The next step then would be sample-collecting and -returning technology," said Ouyang after an annual industry conference in Beijing on Oct 10. "This allows us to know more about the history of the moon and Earth, and also provides us with important physical, chemical, and geological information, which facilitate our future exploration and lunar base establishment."

The moon exploration would not only give China first-handed space science data, but also push the development of cross-subject science forward, such as space astronomy, space physics, and space material science.

But there was no timetable of putting a manned spaceship on the moon at this point, according to Ouyang.